Combining unfold with parallel magnetic resonance imaging
AssigneeThe Brigham and Women's Hospital, Inc.
InventorBruno Madore
Life of this patent
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Abstract
A method for combining UNFOLD with a parallel magnetic resonance imaging (MRI) technique, such as SMASH, SENSE, or SPACE-RIP is provided. When acquiring only one nth of the usual amount of k-space data, data is acquired n times faster, but n signals will overlap in the resulting images. By spreading the n signals over all of the available temporal frequency bandwidth, UNFOLD reduces the amount of overlap to n/2. A parallel imaging method with an acceleration n/2 can finish the reconstruction by separating the n/2 overlapped signals. The result is a time series of non-corrupted images that are acquired n times faster than normal.
Claims20
A method for combining an UNFOLD technique with a parallel MR imaging technique to obtain an MR image of an object, the method comprising:
- a) obtaining k-space information about the object at a first time point and a first set of k-space locations;
- b) obtaining k-space information about the object at a second time point and a second set of k-space locations, wherein at least one of the k-space locations in said second set is not contained in said first set,
- c) obtaining information for images at the first and the second time points using the first and the second sets of k-space data, respectively, said images containing spatially aliased and non-aliased components, the image having image pixels;
- d) decomposing time variations of one of the image pixels into its frequency content;
- e) for a predetermined frequency of the frequency content, using a parallel imaging technique to separate the aliased and the non-aliased components that are overlapped;
- f) repeating step (e) for a plurality of frequencies;
- and
- g) repeating steps (d) through (f) for a plurality of image pixels.
A method for combining an UNFOLD technique with a parallel MR imaging technique to obtain an MR image of an object, the method comprising:
- a) obtaining k-space information about the object at a first time point and a first set of k-space locations;
- b) obtaining k-space information about the object at a second time point and a second set of k-space locations, wherein at least one of the k-space locations in said second set is not contained in said first set,
- c) obtain information for images at the first and the second time points using the first and the second sets of k-space data, respectively, said images containing spatially aliased and non-aliased components, the image having image pixels;
- d) decomposing time variations of one of the image pixels into its frequency content;
- e) for a predetermined frequency of the frequency content, using a parallel imaging technique to separate the aliased and the non-aliased components that are overlapped at the predetermined frequency;
- f) removing the aliased and the non-aliased components that do not exist at the predetermined frequency;
- g) repeating step (e) for a plurality of frequencies ranging from between about DC to about a Nyquist frequency;
- h) repeating steps (d) through (f) for all of the image pixels;
- and
- i) producing an MR image having a field of view being substantially one-half dynamic.
An article of manufacture, comprising:
- a computer usable medium having computer readable program code means embodied therein for combining an UNFOLD technique with a parallel MR imaging technique to obtain an MR image of an object, the computer readable program code means in said article of manufacture comprising:
- (a) computer readable program code means for causing the computer system to obtain k-space information about the object at a first time point and a first set of k-space locations;
- (b) computer readable program code means for causing the computer system to obtain k-space information about the object at a second time point and a second set of k-space locations, wherein at least one of the k-space locations in said second set is not contained in said first set;
- (c) computer readable program code means for causing the computer system to obtain information for images at the first and the second time points using the first and the second sets of k-space data, respectively, said images containing spatially aliased and non-aliased components, the image having image pixels;
- (d) computer readable program code means for causing the computer system to decompose time variations of one of the image pixels into its frequency content
- (e) computer readable program code means for causing the computer system for a predetermined frequency of the frequency content, to use a parallel imaging technique to separate the aliased and the non-aliased components that are overlapped to decompose time variations of one of the image pixels into its frequency content;
- (f) computer readable program code means for causing the computer system to repeatedly use the computer readable program code means (e) for a plurality of frequencies;
- and
- (g) computer readable program code means for causing the computer system to repeatedly use the computer readable program code means (d) through (f) for a plurality of image pixels.
Dependencies are inferred from the claim text.